1. The Field of the Invention
The present invention relates to hand operated throttles for motorized vehicles.
2. The Relevant Technology
Many recreational motor vehicles, such as all-terrain vehicles (ATVs), snowmobiles and personal watercraft require the operator to activate a thumb operated throttle to control the engine. The thumb throttle is usually mounted on or near the right handle bar and has a lever disposed below and behind the right hand grip. As the rider grips the right hand grip, the rider's thumb operates the throttle by pushing the throttle lever from a closed or idle position toward the handle bar and holding it there. The thumb throttle is designed to provide a range of speeds as the lever is pushed forward. If the lever is fully pushed forward with the thumb to the open position, the throttle is held fully open and the highest speeds can be reached. Of course, holding the throttle in between the idle and open positions produces an intermediate level of speed generally proportional to the distance the lever has been pushed.
For safety reasons, one or more springs is used to force the throttle back to the idle position if the throttle lever is released, thus reducing power to the engine. As a result, if the rider releases his or her grip on the throttle lever, the vehicle will automatically slow down or stop. Although the spring provides an important safety function, it also causes fatigue in the rider. Holding the throttle lever against the force of the spring by the thumb can be very tiresome, especially on long trips. This discomfort can be exacerbated by environmental or other variables. For example, when riding a snowmobile or ATV, the outside temperature can be very low, adding to the thumb's discomfort. Moreover, people with smaller hands suffer more because the thumb must be stretched out to grip the throttle. This puts additional strain on the rider.
Several solutions to this problem have been devised. The first is to lengthen the thumb lever and/or reduce the amount of force required to push the lever. While this may help to slow the onset of thumb discomfort, it does not prevent it. The second is to replace the immovable hand grip with one that can rotate about the handlebar. This rotatable hand grip has a projection that pushes on the thumb throttle as the hand grip is rotated, thus allowing the motor vehicle to have a motorcycle-style throttle. Although this makes riding more comfortable, it also makes it more dangerous. The solid grip of the rigid hand grip is lost and makes the operator more susceptible to losing his or her grip while riding, especially during the jostling that can easily occur.
Accordingly, what is needed are finger actuated throttles that can be attached to or otherwise combined with thumb throttles to minimize the discomfort caused by current thumb throttles.